Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Boards > Cranial Nerves > Flashcards

Cranial Nerves Flashcards

1
Q

cranial nerves I and II exit

A

the only two that do not exit the brain at the level of the brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

cranial nerves III and IV exit

A

exit at the level of the midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

cranial nerves V, VI, VII, and VIII exit

A

exit at the level of the pons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cranial nerves IX, X, XI, and XII exit

A

exit at the level of the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

pure motor nerves

A

CN IV, VI, XI, and XII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

eye movements and pupillary contriction

A

III, IV, VI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

pure sensory nerves

A

I, II, VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

mixed nerves

A

V, VII, IX, and X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

parasympathetic fibers

A

III, VII, XI, and X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CN I Olfactory Nerve

A

sensory: responsible for the sense of smell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

CN I Olfactory Nerve: path

A

nerve fibers traverse the skull through the cribriform plate where neurons synapse directly with the cortex with no relay through the thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

CN I Olfactory Nerve: pathology

A

head trauma can cause damage to the olfactory nerve as it travels through the cribriform plate leading to anosmia
olfactory groove meningiomas can also present with anosmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

CN II Optic Nerve

A

sensory: responsible fort visual sensory input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

CN III Oculomotor Nerve

A

motor: innervates numerous extraocular muscles: superior rectus, inferior rectus, medial rectus, and inferior oblique as well as levator palpebrae
parasympathetic: pupillary constrictor and ciliary muscles (efferent limb of the pupillary reflex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

CN III Oculomotor Nerve: pathology

A

oculomotor nerve palsy can present with a combination of four possible clinical features: ptosis, ocular deviation, mydriasis, and diplopia
- ptosis secondary to loss of innervation of levator palpebrae muscle
- ocular deviation (down and out) and diplopia due to unopposed action of the lateral rectus and superior oblique muscles
- mydriasis occurs due to damage to the parasympathetic fibers which supply the pupillary constrictor and ciliary muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

CN III Oculomotor Nerve: path etiologies

A

include trauma, diabetes, hypertension, subarachnoid hemorrhage, and compression from a posterior communicating aneurysm or uncal herniation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

posterior communicating aneurysm

A

compresses the third nerve leading to ipsilateral pupillary dilatation and ophthalmoparesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

CN IV Trochlear Nerve

A

motor: innervates the superior oblique muscle, which is responsible for internal rotation and depression of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

CN IV Trochlear Nerve: pathology

A

exits the brainstem dorsally
of the cranial nerves, CN IV has the longest intracranial course
patients will complain of diplopia and difficulty descending stairs
on exam, patients will often tilt their head away from (contralateral to) the affected side to compensate for extorsion of the ipsilateral eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

CN V Trigeminal Nerve exits

A

at the level of the pons and trifurcates into three branches
- V1 Ophthalmic: traverses the skull through the Superior orbital fissure
- V2 Maxillary: traverses the skull through the foramen Rotundum
- V3 Mandibular: traverses the skull through the foramen Ovale
mnemonic: “Standing Room Only”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

CN V Trigeminal Nerve

A

sensory: responsible for all modalities of sensation to the face
motor: innervates the muscles of mastication (masseter, temporalis, medial, and lateral pterygoids), tensor veli palati, anterior belly of the digastric, mylohyoid, and tensor tympani
- motor fibers exit via foramen ovale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

CN V Trigeminal Nerve: Pathology

A

associated symptoms with a trigeminal lesion include impaired facial sensation and impaired hearing of the ipsilateral ear secondary to damage to the tensor tympani muscle
- can be seen in Wallenberg’s syndrome which is due damage to the lateral medulla from a posterior inferior cerebellar artery (PICA) ischemic stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

trigeminal neuralgia

A

compression of the trigeminal nerve can lead to trigeminal neuralgia which presents with intermittent, severe sharp/stabbing-like paroxysms of the face, episodes usually occur for only a few seconds at a time
sensory exam normal
common triggers: brushing teeth, washing face, and strong winds
carbamazepine first line therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

dura of anterior fossa

A

innervated by ophthalmic branch of trigeminal nerve (CN VI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

dura of posterior fossa

A

predominantly innervated by cervical roots C2 and C3 as well as CN X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

CN VI Abducens Nerve

A

Motor: innervates lateral rectus muscle, which is responsible for lateral deviation (abduction) of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

CN VI Abducens Nerve: pathology

A

lesion to the abducens nerve will lead to dysfunction of the lateral rectus muscle and the unopposed action of the left medial rectus muscle causing the affected eye to be turned nasally
can be secondary to increased ICP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

CN VII Facial Nerve

A

motor: innervates the stapedius, buccinator, posterior belly of the digastric, and muscles of facial expression including frontalis, corrugator, orbicularis oculi and oris, nasalis, mentalis, and platysma
sensory: responsible for lacrimation, salivation (submandibular, sublingual), taste from the anterior 2/3rds tongue and sensation of the external ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

CN VII Facial Nerve: pathology

A

Bell’s palsy is a facial nerve mononeuropathy that presents with acute weakness of upper and lower facial muscles secondary to nonspecific viral infection
- most common cause of facial nerve paralysis
- second most common is HSV reactivation
- treatment: prednisone to reduce inflammation +/- valacyclovir for severe cases
infection related facial mononeuropathies often make a complete or near-complete recovery and rarely recur
non-infectious causes of facial mononeuropathy include sarcoidosis, diabetes, Sjogren’s syndrome, and amyloidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Ramsay Hunt syndrome

A

also called geniculate neuralgia or nervus intermedius neuralgia
paroxysms of severe pain deep in the ear and can present as hearing loss, bitter taste, tinnitus, and vertigo secondary to viral spread to the vestibulocochlear nerve
vesicular rash on external acoustic meatus and lateral tongue

31
Q

ramsay hunt syndrome pathophysiology

A

herpes zoster virus lies latent in geniculate ganglia after initial infection and reactivation causes inflammation of the nerve within the narrow stylomastoid foramen -> damage to the nerve
can cause facial nerve mononeuropathy
more seen in immunocompromised patients

32
Q

CN VII Facial Nerve: taste

A

rarely affected in facial nerve mononeuropathies because taste fibers do not traverse through the stylomastoid foramen
facial nerve lesions proximal to the chorda tympani, which are uncommon, could present with a taste deficit on the ipsilateral side

33
Q

CN VII Facial Nerve: hyperacusis

A

caused by weakness of the stapedius muscle because bone is unable to cover the oval window to protect it from low vibratory tones

34
Q

Lyme disease

A

can cause unilateral or bilateral facial nerve palsies as well as multiple cranial neuropathies

35
Q

CN VIII Vestibulocochlear Nerve exits

A

via the internal acoustic meatus

36
Q

CN VIII Vestibulocochlear Nerve

A

sensory: responsible for auditory sensory input (cochlear nerve) and maintaining equilibrium (vestibular nerve)

37
Q

Auditory Pathway

A

Spiral ganglion -> Superior olivary nucleus and trapezoid body -> Lateral lemniscus -> Inferior colliculus -> Medial geniculate nucleus -> auditory cortex
internal acoustic meatus is SSLIM

38
Q

CN VIII Vestibulocochlear Nerve: pathology

A

BPPV: otoliths -> nausea and positional vertigo
Dx: Dix Hallpike. Tx Epley maneuver

39
Q

brainstem auditory evoked potentials (BAEPs)

A

cochlear nerve represents wave I
if wave I is present without any other waveforms on BAEPs then this is concerning for brain death

40
Q

unilateral peripheral vestibular dysfunction

A

patient falling towards the affected ear

41
Q

CN IX Glossopharyngeal Nerve

A

motor: innervates stylopharyngeus
sensory: responsible for taste of posterior 1/3 tongue, salivation (parotid), and autonomic monitoring via chemo- and baroreceptors of the carotid body and sinus

42
Q

baroreceptor reflex

A

essential in regulating responses to blood pressure changes through changes in sympathetic tone. when blood pressure drops, baroreceptors cause an increase in sympathetic drive to increase heart rate in an attempt to preserve perfusion to the brain.
central locations in the aortic arch and carotid sinus
- aortic arch baroreceptor information travels to the nucleus tractus solitarius, and then to the ventrolateral medulla, via the aortic nerve (Nerve of Cyon), which combines with the vagus nerve (CN X)
- carotid sinus baroreceptor information primarily reaches these same nuclei via the glossopharyngeal nerve (CN XI)

43
Q

CN IX Glossopharyngeal Nerve: pathology

A

glossopharyngeal neuralgia
- presents with intense and paroxysmal pain of the ear and tonsillar fossa which can be triggered by coughing or swallowing
- syncope can occur due to inappropriate carotid sinus/body sensory fiber activation

44
Q

most commonly asked cranial nerve-muscle innervation associations:

A

CN IV: superior oblique
CN VI: lateral rectus
CN V: anterior belly of the digastric and tensor tympani
CN VII: posterior belly of the digastric and stapedius
CN IX: stylopharyngeus

45
Q

CN X Vagus Nerve

A

motor: innervates the muscles of the pharynx and larynx, and only one tongue muscle: palatoglossus
sensory: responsible for taste sensation of the epiglottis as well as visceral sensation of the heart, lungs, and GI tract

46
Q

CN X Vagus Nerve: path

A

derives fibers from the nucleus ambiguus, the dorsal motor nucleus, and the nucleus solitarius
nucleus ambiguus -> branchial motor fibers that travel to the muscles of the pharynx and larynx
dorsal motor nucleus -> parasympathetic innervation to the heart, lungs, and GI tract
nucleus solitarius -> taste and visceral sensory information from the heart, lungs, and GI tract

47
Q

CN X Vagus Nerve: pathology

A

recurrent laryngeal nerve is a pure motor branch of the vagus nerve which innervates the laryngeal muscles.
- damage to this nerve by trauma, thyroid surgery, or compression neoplasm can lead to hoarseness, dysphagia, and hypophonia

48
Q

CN XI Spinal Accessory Nerve

A

motor: sternocleidomastoid and trapezius

49
Q

CN XII Hypoglossal Nerve

A

motor: innervates the extrinsic muscles of the tongue (glenioglossus, hypoglossus, and styloglossus)

50
Q

CN XII Hypoglossal Nerve pathology

A

lesion will lead to tongue deviation toward the pathologic side

51
Q

Cavernous sinus includes

A

several cranial nerves: CN III, IV, VI, V1 and 2, and sympathetic nerve fibers
internal carotid artery
surrounds pituitary gland

52
Q

Cavernous sinus pathology

A

CN VI is the closest to the ICA and is most likely to be damaged in carotid dissection

53
Q

Cavernous Sinus Syndrome

A

presents with papilledema, proptosis, and painful ophthalmoplegia
- proptosis secondary to occlusion of ophthalmic veins
common cause is cavernous sinus thrombosis often secondary to infection from orbital cellulitis or sinusitis
diabetes is risk factor

54
Q

cribriform plate

A

olfactory nerve

55
Q

optic canal

A

optic nerve

56
Q

superior orbital fissure

A

oculomotor, trochlear, abducens, ophthalmic branch of trigeminal

57
Q

foramen rotundum

A

maxillary branch of trigeminal

58
Q

foramen ovale

A

mandibular branch of trigeminal

59
Q

internal auditory meatus

A

facial nerve and vestibulocochlear nerve

60
Q

jugular foramen

A

glossopharyngeal, vagus, and spinal accessory

61
Q

hypoglossal canal

A

hypoglossal nerve

62
Q

foramen magnum

A

ascending fibers of spinal accessory nerve enter before exiting the jugular foramen
also contains medulla and vertebral arteries

63
Q

foramen lacerum

A

contains greater petrosal and deep petrosal nerves
internal carotid artery runs along, but not technically through, this foramen

64
Q

foramen spinosum

A

middle meningeal artery/vein and meningeal branch V3

65
Q

corneal reflex

A

protective blink response
afferent limb: ophthalmic division of trigeminal nerve
efferent limb: facial nerve (VII) which innervates orbicularis oculi

66
Q

pupillary reflex

A

constriction of both eyes in response to light
afferent limb: optic nerve -> pretectal nucleus -> bilateral Edinger Westphal nuclei
efferent limb: oculomotor nerve
- Edinger-Westphal nuclei -> preganglionic parasympathetic fibers to cilliary ganglia via oculomotor neuron -> postanglionic parasympathetic fibers to sphincter muscle of the iris and ciliary muscles
both ipsilateral and contralateral pupillary constriction can give insight into the integrity of the oculomotor nerves

67
Q

pupillary reflex pathology

A

any lesion to the optic nerve can cause loss of both direct and consensual response
lesion to the ipsilateral oculomotor nerve and/or Edinger-Westphal nucleus leads to loss of direct pupillary reflex
lesion to the contralateral oculomotor nerve and/or Edinger-Westphal nucleus leads to loss of consensual pupillary reflex

68
Q

baroreceptor reflex

A

helps regulate blood pressure by detecting changes via a baroreceptor located in the carotid sinus and aortic arch. Increased pressures marked by these receptors produce slower heart rates and drops in blood pressure. A decrease in blood pressure produces an increase in sympathetic tone and a decrease in parasympathetic tone.
afferent limb is the glossopharyngeal nerve for the carotid sinus and the vagus nerve for the aortic arch.
efferent limb is the vagus nerve (CN X).

69
Q

gag reflex

A

afferent limb: glossopharyngeal nerve
efferent limb: vagus nerve

70
Q

nucleus tractus solitarius

A

both taste (rostral nucleus) and baroreceptor (caudal nucleus) information
CN VII: taste to anterior 2/3 tongue
CN IX: taste to posterior 1/3 tongue and baroreceptor from carotid sinus
CN X: taste to the pharynx and baroreceptor from aortic arch
information travels to the VPM of the thalamus

71
Q

nucleus ambiguus

A

corticobulbar input is bilateral
motor fibers to pharynx/larynx/palate via CN IX, X, and XI

72
Q

superior salivatory nucleus

A

parasympathetic supply to oral and nasal cavity lacrimal and mucosal glands, via CN VII

73
Q

inferior salivatory nucleus

A

parasympathetic supply to the parotid gland, via CN IX
remember that although CN VII runs through the parotid gland physically, the gland’s parasympathetic innervation comes from CN IX

Neuro Boards (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions